Carbamide and Hydrogen Peroxide Bleaching Effect on Modern CAD/CAM Dental Ceramics: An Investigation on Ion Release and Surface Characteristics

Objectives: This study aimed to investigate the impact of bleaching agents based on carbamide or hydrogen peroxide on dental ceramics in vitro, utilizing scanning electron microscopy (SEM) and elemental analysis via inductively coupled plasma optical emission spectroscopy (ICP-OES). Methods: CAD/CAM ceramics (IPS e.max®CAD, IPS Empress®CAD, Vitablocs® Mark II, Celtra Duo, and inCoris TZI) were treated with bleaching agents using either 10%, 20%, 30% carbamide peroxide or with 35%, and 40% hydrogen peroxide. Results: Surface elemental release was not significantly affected by the type or concentration of bleaching agent (p>0.05). Ion release in feldspathic ceramics was significantly higher than in other ceramic materials (p<0.0001). Microstructural surface changes were observed in all materials except for lithium disilicate and zirconia-reinforced lithium silicate ceramics. Conclusions: All bleaching agents tested in this study showed a similar impact within each material type tested regarding total mass loss, elemental composition, or surface structure. Clinical relevance: Lithium disilicate and zirconia-reinforced lithium silicate ceramics were the most resistant to bleaching agents. In contrast, feldspathic ceramic showed the highest ion release and surface deterioration when exposed to all bleaching agents tested.

Bleaching Agents CAD/CAM Dental Materials Dental Ceramics Elemental Analysis Ion Release